Push-button switch arranged in multiple rows



Nov. 28, 1950 E. s. MGLARN 2,531,457

PUSH-BUTTON SWITCH ARRANGED IN MULTIPLE ROWS Filed Nov. 13, 1946 3 Sheets-Sheet 2 m64. Www/1 Patented Nov. 28, 1950 PUSH-BUTTON SWITCH ARRANGED IN MULTIPLE ROWS Ernest S. McLarn, Manhasset, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application November 13, 1946, Serial No. 709,668

11 Claims.

The present invention relates to means for interlocking keys applicable particularly, but not exclusively, to a subscribers telephone equipment.

It has been proposed heretofore to provide a subscribers telephone set with manually operable keys individually assigned to certain telephone lines whereby operation of any key will eiect connect'on of said telephone set to the corresponding line of said telephone lines. Each of said keys when operate-:l may be held in operated position until released in some suitable manner. It is also important to provide interlocking means whereby full depression of any two keys at the same time will be prevented and full depression of any key will restore any other depressed key to normal position.

It has also been proposed heretofore in some key-controlled multiple-switch devices to meet this requirement by providing beneath parts of keys arranged in a row, a exible band supported at each side of each key and xed at its ends and providing enough slack to permit full depression of one key at a time.

An important object of the invention is to provide novel and advantageous apparatus of the general character described.

Another object o the invention is to provide apparatus of the general character described including novel and advantageous means for controlling the operation of a pluralty of depressible keys for various purposes, includng that of preventing the full depression and latching in depressed position, of more than one key at a time.

According to one way of carrying out the invention as applied to a subscribers telephone set there is a row of spring supported keys or push buttons each of which when fully depressed will close certain switches and will be yieldingly latched in depressed position. Beneath said keys is a exible band passing through guides located between successive keys and holding the band against upward or downward movement at said guides. Said band is secured at its ends so as to provide just enough slack to permit full depression of one key at a time. When the apparatus is not in use, and all keys are in raised position, the slack is taken up by one arm of a yieldable lever of which the other is pressed down by the support or cradle for the receiver or hand set.

The arms of said lever are limited by structure as to outward movement and are urged outwardly to their limiting positions by a spring device which is not strong enough to lift the receiver or hand set when a key is accidentally depressed, :e

Cal

but is strong enough to restore the key to raised position, even against the action of the spring latch for holding the key depressed.

The key-controlling apparatus may be modified for use Where keys are arranged in a plurality of rows.

In some forms of apparatus, the tautness of the band under the keys when the apparatus is not in use, might be maintained by means other than a receiver or a hand set resting on a corresponding support.

Other objects, features and advantages will appear upon consideration of the foilowing detailed description and of the drawings, in which Fig. 1 is a fragmentary iront elevation of one embodiment of the invention, partially broken away to show underlying structure, with no key depressed and hand set in place on the cradle;

Fig. 2 is a section taken along the line 2--2 of Fig. l, certain parts being broken away; and hand set oii cradle.

Fig. 3 is a View looking in the same direction as in Fig. 1 (but with one key shown locked in depressed position)7 certain parts being in section and other parts being broken away; hand set is off cradle.

Fig. 4 is a section taken along the line 4-4 of Fig. 3;

Fig. 5 is a diagrammatic View illustrating an arrangement wherein two rows of keys are used and the receiver or hand set is on its support or cradle;

Fig. 6 is a view similar to Fig. 5, but with the receiver oil the support and one key of the second set depressed;

Fig. 7 is a fragmentary sectional View taken along the line 'l-'I of Fig. 5; and

Fig. 8 is a fragmentary sectional view along the line 8-8 of Fig. 6.

Referring to the drawings, Figs. l, 2, 3, and 4 illustrate a subscribers station of an inter-coinrounication system wherein there is a single row of keys or push buttons lo, preferably of molded insulating material, and depress'on of any one of these push buttons will connect a hand set Il (Fig. 2) to a corresponding line connected to said subscribers station, if other conditions are met. Said push buttons I!! are in the form of plungers of any suitable cross-section with their lower ends slidably mounted in corresponding openings in a metal plate I2 constituting the top of a frame I3.

The upper parts of said push buttons or plungers l0 are slidably mounted in corresponding openings in the top of a cover l of suitable intaken sulating material such as molded plastic or the like, and provided with reinforcing partitions l@ between the push buttons. Each push button I0 is urged upwardly by a helical spring i5 interposed between plate i2 and a washer I6 which is held against a pin il passing through the plunger". Upward movement'fof the plunger is limited by engagement of the pin I'l with the top of the cover Il; and/or by engagement of the lower face of the plate i2 by the foot or Contact spreader i3 of the plunger or push. button lli. Buttons IQ are held against rotation by the engagement of pins il in slots Ita in cover I4.

The frame I3 has endsliwhich are illustrated as integral with plate t2' and extendingdownwardly at right anglesl thereto. The lower parts of the frame ends l9 are-fastenedby suitable means such as screws 2E! to upturned ends 2i of the bottom of a channel 22 to the sides of which are attached as by screws 23 the lower endso.springassemblies'Zll and Z5 (Fig. 4).. The springs of said pile-ups are, of course, insulated from each other'.v Depression of a. plunger It is utilized 4to effect spreading of inner springs 26 intor contact with adjacent springs Z1 and locking of the plunger l0 in its lowermost or depressed position. To thisV end, springsY 25 are bent, below their upper ends, to provide inward lprojections 23, and theA foot I8 of the plunger is formed with upwardly spreading sides 29 (Fig. 4) to engage and separate projections 28,` and above said sidesl 28- with recesses 38 to receive said projections 28 and lock the push button or plunger in; depressed position, Depression of the push button' or plunger presses the springs 25 25a'V to separate a spring 25D from a spring 25e and through an insulating button 25d to move spring 25e out of contact with spring 25j. At theY same time the right and left hand portions of springs 25 and 2'! are broughtinto contact.

In providing key control and interlocking, use is made of an inextensible exible band'3l, preferably in the form of a ymetal tape extending beneath the lower ends of all of said push buttons I i3. The ends of said tape extend outward-ly through openings 32 and over curved-surface supports' 3sv formed by curvingl inwardly the material of ends E9 at the lower edges of said openings 32. The tape is clamped between ends I9 and plates 35i by means such as screws 3-5. The ribbon or tape 3i may be made of various materials so long as it has suicient' strength, flexibility and. non-elasticity. Use might be made of a bronze tape, a metal braided ribbon or tape or a fabric treated with rubber or plastic.

If stretched between said supports 33, the flexible band or ribbon 3! will be substantially in contact with the bottomfaces of the plungers l d inV raised positions. These bottom faces are straight from front to rear of Figs. l and 3, as

' l2 and attached thereto by suitable means as screws 3i. The partition 15a of the cover i4 are directly over the guides 35 and the cover is secured to the plate l2 by screws 31a. Near the lower ends of guides 36 are guide passages 38 for the tape 3l, with curved tops and bottoms to avoid sharp bends in the tape. The low central parts of said passages hold the correspondingportions of the tape at the same level as the curved surfaces or guides 33.

There is just enough slack in the tape 3i between the frame ends i9, so that full depression of any one key will prevent depression of any other key'. However, in the apparatus of the present invention, there is further control effected by placing the receiver or hand set L! onY or removing it from a support or cradle 39 in'which ismounted an upwardly and downwardly movable member or plunger il pressed upwardly by a spring 40a. An inclined or cam surface on one side of plunger 4o engages a roller 4017 carried by a springv 46c of a spring assembly 49d. Asseen from Fig. 2- the upward. movement of plungerlt effects the closing of. the leftl hand contacts of assembly 49dby spring fiile. and the downward movement of plunger 40, the opening of. these contacts and the closingY of thel right hand contacts of theassembly. Spring ABC. engages anarrrr Moi a lever` 42. which alsoY includes asecond arm 43. yieldably connected to theflrst arm 42T. The: inner ends of these arms are pivotally mounted side by side on a pin 41! supported by two lugsila extending downwardly from plate t2.. Upward movement of the two arms is limited by engagement of. a lug 4-5 on a-rm by a pin Lil-i3Y extending laterally into the path of lug 45, and the two arms are urged to suchf limiting positions by a spring M wound around said pin and having parts here shown as loops. itV and 4.53,. engaging` said arms fromA below.

Thearmr G3. is provided withan oil-turned forward endV 553. having a curved upper surface to engage ther lower side of the tape and prevent bending of the tape oyer a sharpV edge; When the hand set Il is on the cradle and no key is depressed, the slack in the tape 3 t will be taken up by the arm ASV-as shownin--Fig 1. The spring-ill is not strong enough. to lift the hand set [l through the cradle 3S. Under these circumstances any oneV of said keys may be depressed, accidentally or otherwise, and pull down the lever arm 4.3,. soA that the projections 23 will'engage saidl recesses or notches 3S (Fig. 4). Of course, no other key could be-depressed at the same time. However, the spring- 4l is strong enough to restore thedepressed key le to its normal or unoperated position. Y

When it is found desirable to use the hand set or. receiver H, it may be lifted from thesupport or. cradle 35i. This will release the lever i2 and enableV it to take its Fig. 2 position and shift the springs of the spring assembly accordingly from positions wherein spring 40e. is in contact with the right hand spring of the spring assembly (Kid. and all contacts to the left of spring .ic are broken. Then the .depression of any one of said keys, for example the. left in Fig. 3, will prevent the depression of other keys of said set.

The operation oi the apparatus will now be reviewed. Depression of a key ii) should be effected orly when the hand set ti has been removed from the support or cradle 39, leaving the parts in the generali condition shown: in Fig. 3l Then a selected key i3 may be depressed to effect connection with a desired line and the key will be latched in depressed position by engagement of projec- Y tions 28 of springs 29 in recesses 30. Theta-pe3l and the cooperating parts prevent the depression of two keys at the same time.

If it be desired merely to disconnect a line in use, the desired result may be obtained by partially depressing any non-operated button, by restoring the hand set to the support or cradle thereof or by depressing the support by hand. If it be desired to change connection from one line to another, this result is achieved merely by depressing the proper key which would restore to normal position the key previously depressed.

It is not intended to depress a key while the hand set is on the cradle. However, if a key be depressed at this time either accidentally or intentionally, the spring 41 would yield without lifting the hand set and as soon as the pressure on the key is removed, it will be rturned to its normal position.

Up to this point the invention has been described only with reference to a single row of keys. However, the invention can be applied to a modified apparatus having a plurality of rows of keys, a form having two rows of keys being illustrated in Figs. 5 through 8 wherein parts connected with the first row of keys are designated by the same numerals as in Figs. 1 through 4 but with the subscript a associated therewith, and the corresponding parts connected with the second row are designated by the same numerals but with the subscript b.

In Fig. 5, keys I b of the second row are to the front, parts oi these keys being broken away to show parts of keys lila of the rst set to the rear thereof. In order that the taking up of slack in either of the tapes 3Ia and 3Ib may cause the taking up of slack in the other, the frame ib is extended to the right and a tape guide 36h provided to the right of the right-hand plunger lb. Midway between the right-hand tape guide 35h and the curved top support 33h, the tape 3!l1 underlies the transversely curved lower face of the corresponding end 5Ib of a lever 5| mounted midway of its ends on a horizontal pivot 52 and at the other end 5|a the tape 3Ia also underlies the lever, as indicated clearly in Figs. 7 and 8. When the lever arm 43 is in raised position (Fig. 5), the tape Sia is horizontal at all other points. The lever end 51a is then in raised position and the lever end 5Ib is in lowered position, thus making a bend in tape Sib and drawing the rest of the tape 3 i b into a straight line to prevent depression of any key l9b. The same eiTect would be produced if the arm 43 were in its Fig. 6 position and one of the keys or buttons a were depressed.

If one of the keys Ib be depressed to force the tape 3lb down at that position (Fig. 6), the res?J of the tape would be drawn straight and end 51h of lever 5l would be raised. This would cause end 51a to be depressed and tape Sia to be depressed at that point, and the rest of tape 31a to be drawn tight, thus preventing depression of any key lila. If the receiver or hand set, whichever it may be, be placed on the hook, any key Illa or lob may be operated against spring action, and when released from pressure from above. would immediately be restored to its upper or normal position.

Obviously, the means for controlling the operation of each of the tapes 31a and 3Ib from the other, might be provided in other forms. For example, this might be done by using a lever pivoted about a vertical axis and having its ends attached to the right hand ends of said tapes. With this arrangement, each end of the lever would move about twice as far as with the other arrangement.

It will be evident that the present invention may be used to very great advantage, especially in certain telephone installations.

It should be understood that various changes may be made and certain features may be used without others, without departing from the true spirit and scope of the invention.

I claim:

l. In a multiple switch device, a row of springsupported push buttons, switches individual thereto and operated by depressing the corresponding push buttons, an inextensible tape beneath the lower ends of said push buttons, means to maintain said tape at a uniform level at opposite sides of each push button, means for holding the ends of said tape with enough slack therebetween to permit full switch operating depression of one button at a time, said tape being operatively positioned after full depression of any one of said push buttons to return said push button to an unoperated position by partially depressing any nonoperated button.

2. The combination according to claim 1 wherein each switch comprises at opposite sides of the tape upright contact springs formed with inward projections near their upper ends, and the corresponding push button has a foot provided with a lower face straight in a direction across the tape to cooperate therewith, outwardly and upwardly inclined faces to engage said projections and cam them outwardly, and recesses above said inclined faces to receive said inward projections and yieldably latch the push button in depressed position.

3. The combination according to claim 1 wherein there is a spring device settable to engage said tape and take up the slack when the push buttons are raised or settable to ineffective condition, and means to yieldingly latch a fully depressed push button in that position, said means to yieldably latch a push button operative to be overcome by said spring device when the latter is set to take up the slack.

4. The combination according to claim 1 wherein each push button and the switch operated thereby have cooperating means for yieldably latching the push button in depressed position.

5. In a multiple switch device, a plurality of rows of push buttons and means for yieldably holding them in their idle outward positions, switches individual to said push buttons, inextensible tapes individual to said rows and extending beneath the lower ends of the push buttons therein means to maintain each tape at a uniform level at opposite sides of each push button in the corresponding row, means for holding the ends of each tape with enough slack to permit full switch-operating depression of anv one push button at a time, means interposed between each tape and the tape of another row to transmit motion therebetween and bv full depression of any one push button in anv of said rows prevent full depression of anv other push button therein and means controllable by any of said push buttons to return all said push buttons to an unoperated position.

6. The combination according to claim 5 including yieldable means to latch each push button in depressed position` and additional means acting on one of said tapes to restore a depressed push button associated with any of said tapes.

'7. The combination according' to claim 5 with spring means settable to ineiective condition vand to effective' condition toA exert tension on one of. said tapes, said spring means yielding to suicient pressure to permit depression ofany one of :saidpush buttons` but acting when said pressure `is relieved. to restore the depressedrpush button to its normal position,

8. In a telephone` subscribersVintercommunication system, a row of switches to establishcon- .1

nection with individual telephones, a row of spring-supported push buttons individual to said switches and adapted vwhen depressed to vclose the switches, said push buttons and correspond- -ing switches having cooperating meansfor yieldably latchinga Adepressed push button, an ineX- tensible tape beneath said push-buttons, tape guidesfat oppositesides ofieach of said push buttons, means for holding the ends of said tape leaving sufficient .slack to permit depression of vone push Ybutton at a time, an instrument including areceiver, a member depressed by` placin said instrument thereon and rising when said instrumentis'removed, and yielding means ren- -dered eiective by placing said instrument on said 10. The combination according to claim .8 wherein said yielding means is a yieldable lever one arm of which is pressed downwardly bysaid instrument and the other of which presses upwardly on the tape to tension the same, the arms being limited as to upward movement and being urged in that direction by a spring to tension the tape, said spring being of sufiicient strength to overcome said yieldable latching means.

11. In a multiple switch device, two rows of switches, two rows of spring-supported push buttons individual to said switches for operating the same, and means to prevent full depression of more than one of said push buttons at a time including an inextensible tape under the push buttons of each of said rows and means for transmitting tension from one of said tapes to the other.

ERNEST S. MCLARN.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 570,812 McConnell Nov. 3, 1896 '701,282 Bassett June 3, 1902 931,331 McQuarrie Aug. 17, 1909 984,686 Manson Feb. 21, 1911 1,333,596 Andrick Mar. 16, 1920 2,248,539 Shaw July 8, 1941 2,320,774 Flynt June 1, 1943 2,338,757 Curran Jan-11, 1944 

